高频预提升和补偿在双绞线视频传输中的运用

在监控系统中用双绞线传输视频信号时，高频往往跌落很多。该文讨论一种预提升和补偿的办法，对不同长度的双绞线在传输高频信号时进行不同的补偿，使输出的视频图像信号得到很好的补偿效果，再加上驱动器和接收器，使用双绞线来传视频图像信号的长度可以达到１ｋｍ以上。     

运算放大器在船舶电气中的应用

运算放大器在船舶电气中的应用徐建华（浙江水产学院机械系，舟山３１６１０１）ＡＮＡＰＰＬＩＣＡＴＩＯＮＯＦＯＰＥＲＡＴＩＯＮＡＬＡＭＰＬＩＦＩＥＲＩＮＳＨＩＰＥＬＥＣＴＲＩＣＩＴＹＸｕＪｉａｎｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｃｈｉｎｅｒｙ，ＺＦＣ，...     

基于PID控制的激光器稳频实验研究

应用PID控制原理,设计基于OP27型运算放大器的模拟PI控制电路。利用光学谐振腔稳定的谐振谱线作为锁相放大器的输入,通过锁相放大器内部的运算得出误差信号,将此信号作为PI控制电路的输入信号。PI控制输出信号反馈给激光器调制端口,以达到稳定激光器输出频率的效果。     

CDY—2型矿山压力测定仪设计

本文对新型CDY—2型矿压测定仪的原理和设计作了详细的介绍,给出了各部分电路图,并阐述了用运算放大器组成的信号发生器、选频放大器、检波电路所得到的信号稳定,选频放大效果好、线性度好的显著优点。并提出运放电源用直流变换器,既有利于安全火花的要求,又缩小了仪表的体积。     

用APPLE-Ⅱ微机测量空气中的声速

本文利用ＡＰＰＥＬⅡ微机及其接口技术，实现声信号的快速采集，并利用微机的数据处理功能，对信号进行谱分析和运算，从而实现声速的快速和精确测量．     

一种新型电流镜运算跨导放大器的设计

针对传统低压微功耗电流镜运算跨导放大器存在低增益和小摆率的缺陷,设计了一款新型电流镜运算跨导放大器。在不影响电路的静态功耗和稳定性的基础上,该运算跨导放大器采用增益提高(gain-boosting, GB)结构,增大了电路的小信号增益;引入开关型摆率增强(switched slew-rate enhancement, SSRE)结构,提高了电路的大信号摆率。基于UMC 0.11μm标准CMOS工艺进行电路设计和仿真。仿真结果表明：在1.2 V电源电压和10 pF负载电容下,与传统电流镜运算跨导放大器相比,设计的新型电流镜运算跨导放大器的增益提高了47 dB,正摆率提高了11.2倍,负摆率提高了12.4倍。     

低噪声水声信号前置放大器设计

水下信息的发送与接收主要通过声信号的传播,水听器作为常用的水声信号接收装置,需要前置放大器来提高所获取信号的质量。文中选用AD8421仪表放大器芯片与OP2177精密运算放大器芯片设计了一种低噪声水声信号前置放大器,该电路增益为26 dB,工作带宽为100 Hz～20 kHz,输出信号为差分形式,同时具有小体积、低功耗的特点。通过连接某型压电水听器,测试了电路工作性能以及对水听器信号的调理效果。实测结果表明,该前置放大器能满足设计技术指标要求,在实际工作中取得了良好的效果。     

一种简单实用的线性光隔离放大器

本文介绍由运算放大器ＬＭ３５和光电耦合器４Ｎ２组成的光隔离线性放大器，及其调整方法。     

应用于宽带Δ-∑ ADC的多级运算放大器

为提高运算放大器的带内增益和带宽,提出了一款应用于长期演进(LTE)接收机中宽带Δ-∑模数转换器(ADC)的四级运算放大器.该运算放大器采用前馈Gm-C和密勒补偿相结合的混合型频率补偿方法,以保证运算放大器的稳定性.文中采用0.13μm1P6M CMOS工艺设计了一款高性能的四级运算放大器,并将该运算放大器应用于宽带Δ-∑ADC中.测试结果显示:该运算放大器在1.5 V供电电压下可获得72.8 d B的直流增益、442 MHz的增益带宽积和101 V/μs的转换率;在相同的功耗和带宽下,该放大器的带内(0~10 MHz)增益比传统的两级放大器提高了6 d B以上;采用该运算放大器的宽带Δ-∑ADC在10 MHz的信号带宽下具有68 d B的信噪比和78 d B的无杂散动态范围.     

以快速旋转器为运算核的VLSI变换微处理器

当前的ＶＬＳＩ数字信号处理器都以乘加器为运算单元，去完成各种正交变换，常会遇到稳定性问题。该文提出了一类新型的以快速旋转器为运算核的ＶＬＳＩ变换微处理器，它能以最佳的数值稳定性高效地完成用Ｇｉｖｅｎｓ旋转序列实现的各种正交变换。结合图像处理应用的实际需要，设计了包含三个并行的ＴＦＥ变换机的ＰＴＦＥ试验芯片，采用０．８μｍ双层金属ＣＭＯＳ工艺制造，测试表明，功能正确，工作频率达到４０ＭＨｚ，具有高达９６０×１０６ｓ－１移加的运算吞吐率。芯片具有高度的灵活性、可编程性和可扩展性。与该芯片配合，开发了一个针对图像处理中常用变换、按照ＰＴＦＥ硬件控制信号格式产生指令序列的编译器。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with